Data storage systems are arrangements of hardware and software that include one or more storage processors coupled to arrays of non-volatile storage devices, such as magnetic disk drives, electronic flash drives, and/or optical drives, for example. The storage processors service storage requests, arriving from host machines (“hosts”), which specify files or other data elements to be written, read, created, or deleted, for example. Software running on the storage processors manages incoming storage requests and performs various data processing tasks to organize and secure the data elements stored on the non-volatile storage devices.
Data storage systems commonly support migration of data objects, such as file systems and LUNs (Logical Unit Numbers, referring also to the units themselves), from one data storage system to another. Migration may be performed for numerous reasons, such as to provide a higher service level, e.g., by hosting data objects from faster disk drives. A storage administrator may direct migration of a data object by selecting the data object on a source data storage system and specifying a destination data storage system as a target. The two data storage systems coordinate to move the contents of the data object from source to destination. After migration, hosts can access the data object from the destination. Some data storage systems include multiple storage pools providing different service levels. Thus, migration may also be performed between different pools of a single data storage system.
Data storage systems may use LUNs to provide storage for virtual machines (VMs). For example, a LUN may store many virtual machine disks. If a VM administrator wishes to obtain a higher service level for one or more VMs whose virtual machine disks are stored on a LUN, the VM administrator may coordinate with a storage administrator, who can migrate the LUN from one data storage system to another, or from one pool to another.